其他
R可视化11|ggplot2-图层图形语法 (3)
"pythonic生物人"的第109篇分享
本文系统介绍ggplot2的统计变换（stat）、位置设置（Position adjustments）和标度（scale）。
本文目录
6、统计变换（stat）
stats can be created with a geom_ function
stats can’t be created with a geom_ function
7、 位置设置（Position adjustments）
条形图中stack|fill|dodge
散点图中nudge|jitter|jitterdodge
8、标度（scale）
marker的形状和大小
图例和坐标轴
6、统计变换（stat）
将data经过一种统计方法整理，然后再绘图，ggplot2的统计方法如下，都是以stat_开头的函数。
可以分为两类：
stats can be created with a geom_ function
stat_bin():geom_bar(),geom_freqpoly(),geom_histogram()stat_bin2d():geom_bin2d()stat_bindot():geom_dotplot()stat_binhex():geom_hex()stat_boxplot():geom_boxplot()stat_contour():geom_contour()stat_quantile():geom_quantile()stat_smooth():geom_smooth()stat_sum():geom_count()
options(repr.plot.width = 4.5, repr.plot.height = 3, repr.plot.res = 300)
f <- ggplot(mpg, aes(class, hwy))
f + geom_boxplot()
stats can’t be created with a geom_ function
stat_ecdf(): compute a empirical cumulative distribution plot.stat_function(): compute y values from a function of x values.stat_summary(): summarise y values at distinct x values.stat_summary2d(),stat_summary_hex(): summarise binned values.stat_qq(): perform calculations for a quantile-quantile plot.stat_spoke(): convert angle and radius to position.stat_unique(): remove duplicated rows.
ggplot(mpg, aes(trans, cty)) +
geom_point() +
stat_summary(geom = "point", fun = "mean", colour = "red", size = 4)
7、 位置设置（Position adjustments）
条形图中stack|fill|dodge
position_stack(): stack overlapping bars (or areas) on top of each other.position_fill(): stack overlapping bars, scaling so the top is always at 1.position_dodge(): place overlapping bars (or boxplots) side-by-side.
options(repr.plot.width = 4.5, repr.plot.height = 5, repr.plot.res = 300)
dplot <- ggplot(diamonds, aes(color, fill = cut)) +
xlab(NULL) + ylab(NULL) + theme(legend.position = "none")
p1 <- dplot + geom_bar()#默认堆叠
p2 <- dplot + geom_bar(position = "fill")#堆叠且按比例
p3 <- dplot + geom_bar(position = "dodge")#并列
p4 <- grid.arrange(p1,p2,p3,nrow = 3)
ggsave("scale23.png", p4, width = 4.5, height = 5)
散点图中nudge|jitter|jitterdodge
position_nudge(): move points by a fixed offset.position_jitter(): add a little random noise to every position.position_jitterdodge(): dodge points within groups, then add a little random noise.
p1 <- ggplot(mpg, aes(displ, hwy)) +
geom_point(position = "jitter")
p2 <- ggplot(mpg, aes(displ, hwy)) +
geom_point(position = position_jitter(width = 0.05, height = 0.5))
p3 <- ggplot(mpg, aes(displ, hwy)) +
geom_jitter(width = 0.05, height = 0.5)
p4 <- grid.arrange(p1,p2,p3,nrow = 3)
ggsave("scale24.png", p4, width = 4.5, height = 5)
8、标度（scale）
marker的形状和大小
使用第一行的数字即可使用第二行的形状。
options(repr.plot.width = 6.5, repr.plot.height = 5, repr.plot.res = 300)
#marker形状
p <- e + geom_point(aes(shape = fl, size = cyl))
p1 <- p + scale_shape() + scale_size()
p2 <- p + scale_shape_manual(values = c(1:26))#values = c(1:26)指定marker
#marker大小
p3 <- p + scale_radius(range = c(1,6))
p4 <- p + scale_size_area(max_size = 6)
p5 <- grid.arrange(p2,p3,p4,nrow = 2)
ggsave("scale25.png", p5, width = 4.5, height = 5)
图例和坐标轴
本文结束，更多好文：
有意见请移步到QQ群629562529反馈，一起进步哈！